|
|
|
Corn
Volume 61 Number 1 Date 04/28/2016 BLACK CUTWORM - The annual black cutworm trapping survey has yielded 676 moths in 39 traps this month, the largest April moth count since 2012. The migrants were carried into the state on storm fronts beginning March 29, with significant flights of 133 and 494 moths occurring in the last two weeks. Large-scale, early migrations such as this one should be considered an early warning of damaging cutworm populations next month. A peak corn cutting period starting May 20 has been projected for Janesville and other far southern Wisconsin locations based on the biofix date of April 17. The primary corn cutting window is expected to open on May 23 in the Wautoma area of central Wisconsin and by May 26 for Wausau and other northern areas. The map below summarizes the cumulative moth counts for the period of March 29-April 27. EUROPEAN CORN BORER - According to the results of last fall's survey, the overwintered generation of larvae should produce an extremely small flight of moths next month. The 2015 European corn borer survey documented a statewide average of only 0.02 borers per plant, or two per 100 plants, the lowest fall population in the last 74 years. Pupation is likely to begin by May 3 in advanced areas of southern Wisconsin. TRUE ARMYWORM - Counts in black light traps increased markedly this week. The first seven moths of the 2016 season were registered at Janesville from April 13-19, which was one week later than their arrival date last year. Another 136 moths were captured from April 21-27 near Janesville and Sparta. Cover crops, spring-killed alfalfa, and small grains will provide attractive oviposition sites for the migrant moths arriving this month. No-tillage fields previously in sod or with small grain cover crops that were not burned down with herbicides early enough in spring usually experience greater true armyworm problems than do conventional tillage fields. -- Krista Hamilton, DATCP Entomologist 
.jpg)
|
|